1. Field of the Invention
The present invention relates to an ink composition, an ink container, and an ink jet recording method.
2. Description of the Related Art
As an image recording method for forming an image on a recording medium such as paper based on image data signals, there are an electrophotographic system, a sublimation type and melt type thermal transfer system, an ink jet system, and the like.
With regard to the ink jet system, since the printing apparatus is inexpensive, it is not necessary to use a plate in the printing, and an image is formed directly on a recording medium by discharging an ink composition only on a desired image area, the ink composition can be used efficiently, and particularly in the case of small lot production, the running costs are low. In addition, the ink jet system causes little noise and is excellent as an image recording system, and thus, it has been attracting attention recently.
Among them, an ink jet recording ink composition which is curable by irradiation with radioactive rays such as ultraviolet rays and the like (radioactive ray-curable ink jet recording ink composition), is excellent from the viewpoint of it being possible to print on various types of recording media because, as compared with solvent-based ink compositions, the drying properties are excellent and an image is resistant to bleeding since most of the components in the ink composition are cured by irradiation with radioactive rays such as ultraviolet rays.
In addition, examples of ink compositions or ink containers in the related art include those described in JP2007-283753A, JP2011-16362A, and JP2004-196936A. JP2007-283753A and JP2011-16362A each disclose an ink-storing body including a photocurable ink composition and air being filled in a container, wherein the dissolved oxygen content in the ink composition is maintained at 3 ppm or more with an upper limit being from 5 to 6 ppm. JP2004-196936A discloses an ultraviolet ray-curable ink jet ink, which is an aqueous ink having a dissolved oxygen content in the ink at 25° C. of from 0.1 to 2 ppm.